Improvement in sheet-metal-straightening machines



C. MARSHALL.

SHEET-METAL STRAIGHTENING MACHINE. No.1 75,365.

Patented March 28,1876..

'UNITED STATES PATENT QFFIOE.

oALEB MARSHALL, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN SHEET-METAL STRAIGHT ENING MACHINES.

Specification forming part of Letters Patent No. 175,365, datedMarch 28, 1876 application filed January 31, 1876.

To all whom it may concern:

Be it known that I, CALEB MARsHALL, of the city of Philadelphia, in the State'of Pennsylvania, have invented a new and useful Machine for Straightening Sheet Metal; and I do hereby declare the following to be a full and correct description of the same, reference being bad to the accompanying drawings, in which 7 Figure l is a rearele-vation of the machine. Fig. 2 is avertical section on line :12 a of Fig. 1. Fig. 3 is an end elevation.

The same part is marked by the same letter of reference wherever it occurs.

The nature of my invention consists in the peculiar construction of a machine in which a serics of fixed and movable rollers and an inclined adjustable plate are so combined and arranged for conjoint operation as to be adapted to remove from metallic plates all kinks, bends,

and buckles, and make them straight and flat, all as hereinafter more particularly set forth.

In the drawings, F F mark two parallel cylindrical rollers, running in strong housings in the sides of the framing. Between these is placed a small roller, A, very slightly tapering from the middle toward either end, as shown in Fig. 1., A row of fixed rollers, B BB B, turn on journals 1) b in the sides of the frame.

' Their lower surfaces are designed to be all in oted at e, and can be raised or lowered at the will of the person operating the machine. Beyond the lower roll F, on the outgoing side, is an inclined plate, E, adjustable by means of the slots 8 and set-screws z. Screws H, operated by levers J, regulate the pressure of the rollers upon the plate to be operated upon. Sis a plate of sheet metal passing through the machine.

The operation is as follows: When the vibrating frame G is down the end of the metal sheet to be operated upon is inserted between the rolls 0 G and B B B, and in the bite of the rolls Bkand F. The operator then places his foot on the treadle D, and raises the rolls 0 0, so as to make short bends in thesheet between the rolls 0 and B, as shown in Fig.

2, as the sheetis drawn in by the large rolls F F, driven by any suitable power. As the sheet is constantly bent back and forth in passing between these rolls, the buckles and curvature imparted by the last pair of rolls,

and deliver the sheet perfectly flat and straight. The roll A, running between rolls F and F, is turned slightly barrel-shaped'or tapering from tha middle toward the ends, so as to compensate for any spring in the large rolls. This roller A being of smaller diameter-than the large rolls, its surface is constantly changing relatively to the surfaces of those rolls, thus preventing them from wearing in grooves or spots. The pressure between the large rolls is controlled by the screws H H, and is made at all times sufficient to take out any inequalities or indentations that may exist in the sheet.

' Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is-

l. The combination of the fixed rollers BB B with the vibrating frame G, provided with the rollers G (J, and operated by the treadle D, in the manner and for the purpose set forth.

2. The combination, with rollers A, B, and F, of the inclined adjustable plate E, arranged and operating in the manner and for the purpose of removing the curvature imparted by the action of said rollers, as stated.

3. The roller A, having the double tapering shape described, and placed between the large rollers F F, in the manner and for the purpose indicated. I

The above specification of my said invention signed and witnessed at Philadelphia this 24th day of January, A. D. 1876.

CALEB MARSHALL.

Witnesses; JOHN DEVLIN, MICHAEL QUINN. 

